kvpb: handle Prepare Transaction requests

Epic: none
Release note: None

Author: stevendanna

pkg/ccl/multitenantccl/tenantcapabilitiesccl/testdata/can_prepare_txns

@@ -28,7 +28,7 @@ ok
 exec-privileged-op-tenant
 PREPARE TRANSACTION 'txn1'
 ----
-pq: ba: QueryIntent [/Tenant/10/Table/104/1/1/0], EndTxn(commit) [/Tenant/10/Table/104/1/1/0], [txn: ‹×›], [can-forward-ts] RPC error: rpc error: code = Unauthenticated desc = client tenant does not have capability "can_prepare_txns" (*kvpb.EndTxnRequest)
+pq: ba: QueryIntent [/Tenant/10/Table/104/1/1/0], EndTxn(prepare) [/Tenant/10/Table/104/1/1/0], [txn: ‹×›], [can-forward-ts] RPC error: rpc error: code = Unauthenticated desc = client tenant does not have capability "can_prepare_txns" (*kvpb.EndTxnRequest)
 
 
 # Grant the capability.
@@ -78,7 +78,7 @@ ok
 exec-privileged-op-tenant
 PREPARE TRANSACTION 'txn3'
 ----
-pq: ba: QueryIntent [/Tenant/10/Table/104/1/1/0], EndTxn(commit) [/Tenant/10/Table/104/1/1/0], [txn: ‹×›], [can-forward-ts] RPC error: rpc error: code = Unauthenticated desc = client tenant does not have capability "can_prepare_txns" (*kvpb.EndTxnRequest)
+pq: ba: QueryIntent [/Tenant/10/Table/104/1/1/0], EndTxn(prepare) [/Tenant/10/Table/104/1/1/0], [txn: ‹×›], [can-forward-ts] RPC error: rpc error: code = Unauthenticated desc = client tenant does not have capability "can_prepare_txns" (*kvpb.EndTxnRequest)
 
 
 # However, transactions that have not acquired locks are able to be prepared,

pkg/kv/kvpb/api.go

@@ -248,7 +248,9 @@ var _ SafeFormatterRequest = (*EndTxnRequest)(nil)
 func (etr *EndTxnRequest) SafeFormat(s redact.SafePrinter, _ rune) {
 	s.Printf("%s(", etr.Method())
 	if etr.Commit {
-		if etr.IsParallelCommit() {
+		if etr.Prepare {
+			s.Printf("prepare")
+		} else if etr.IsParallelCommit() {
 			s.Printf("parallel commit")
 		} else {
 			s.Printf("commit")